Tamping machine



NOV. 9, 1937. W, VELTEN 2,098,895

TAMPING MACHINE Filed April 4, 1935 Illmm wiwi uw l ratented Nov. 9,1937 UNITED STATE 'nimma moms Wilhelm Lothar Velten, Neustadt a. d.Hardt, Germany Application April 4,

In Germany 8 Claims.

This invention relates to machine for compressing and tamping ground orfor the production of all kinds of road, such as road covers,groundworks for railways, sporting grounds and others.

The machine is destined for tamping or compressing the upper layer ofthe ground, be it natural soil or artlcial ground, the irregular packingstone layer, the layer of piece stones or buttress stones, the coverlayer or the like. This machine is tted on its ends with tamping tools,rams or the like adapted to be moved over the ground and adjustablerelative to succession, speed and effect of blow. The stone covercompletely rammed is then covered with a layer of desired thickness ofcommon concrete of damp concrete containing little water, this layerbeing rammed and compressed also by means of the machine with the aid ofsuitable rams or tamping tools so that the machine runs directly on thestone layer or on the concrete. The tamping effect of several singlerams arranged in rows on the end of the machine or of other rammingtools is preferably utilized, said tools beating in alternatingsuccession upon the ground actually tobe compressed, so that by theindividual working on smallest areas of ground a total surface isobtained which is uniformly compressed throughout. This is of greatestimportance for the durability of the road cover, as no so-called waterpockets and the like can form which, asis known, exert a decomposingaction upon the substructure and the permanent way. In the methodaccording to the invention provision is further made Yto add stonematerial or known binding matters, such as tar, bitumen or the likebetween a front row of rams serving for ramming and a rear row of ramsserving for iinal ramming, this addition being regulated by the sameramming vehicle by hand or mechanically. A,

An exclusively mechanical treatment of the individual ground layers isthus ensured, and it is no longer necessary to fill by hand theinnumerable gaps in the stone layers, as by the adjustable rammingeffect of the machine capable to run directly on the individual layersthe best jamming and compressing of the layers is obtained, such as isimpossible by manual labor or with the aid o f the commonly used roadrollers. 'I'he durability of a track produced with the aid of themachine i. e. a road or the like, is much greater than that of thehitherto built tracks as, according to the new method, a compression ora pressure is exerted by the rapidly succeeding blows of the p rammingtools striking perpendicularly upon the ground as cannot be obtained'even to a traction 193s. serai No. 14,614

.rune 14, 1934 (Cl. SHQ) by the subsequent strongest stressing of thetrack.

The invention is illustrated by way of example in the accompanyingdrawing in which:-

Flg. 1 shows in cross-section a track produced according to thenewmethod.

Fig. 2 shows the ramming machine in side elevation partly in section.

Fig. 3 is a part top plan view of Fig. 1, a row oi' rams being exposed.

Fig. 4; is an end view o1' a part of the machine.

Fig. 5 shows in side elevation and part section a modied construction ofthe machine.

A more or less strong compression is imparted to the deposited ornatural ground by a machine running over the ground and equipped withendless tracks or wheels, which has tamping tools, rams or the like andwhich are generally adjustable and adapted to be regulated las regardstheir blow succession, running speed and ramming effect. On either sideof the bed I of the road thus 20 prepared a border of more or less greatWidth of stones 2 standing on edge is inserted, preferably slightlydeeper than the surface of the ground. 'Ihe space between the borders isfilled with packing layer 3 of broken stones on which layer a layer 25 4of broken stones is laid. Instead of packing layer 3 of broken stonesand the covering layer 4 of broken stones a layer 5 and 6 of coarse orne broken stones may be laid. Some gravel is preferably mixed with everylayer. The ramming 30 machine is run over this road substructure, firston the two edges of the road in order to obtain a thorough wedging ofthe stone borders 2. Only then the middle of the road is compressed. Asthe middle portion can no longer yield, owing to the 35 wedging of thestone borders, the entire stone material is well compressed so thatveryfewvery small hollow spaces remain. A lower coarse layer 'l ofcommon. concrete is then laid, this concrete being only damp andcontains little water. The layer is 4 rammed by means of the samemachine running directly on the concrete. This is possible as theramming tools of the machine project laterally beyond the endless track9' and running wheels 45 9 which therefore move on a cover or trackwhich has already been rammed and compressed. On to this concrete layera last upper concrete layer 8 is laid, consisting also, of only dampconcrete containing little water and being fine grained, this 50 layerbeing then also compressed by means of the machine specially built forthis purpose. The nal `treatment of the road surface can then be carriedout in known manner according to the V existing conditions.

method is a motor vehicle.

Inthe irontandrearpartsofthevehiclerows of rams, formed by several ramsor tamping tools are arranged transversely to the direction of traveland in such a manner that the extreme rams cover the wheels of themachine on the outer side so that the ground or track can be rammed andcompressed over its complete width and length, the wheels running onground which has been rammed already. The rows of rams which are infront in the direction of'travel serve for the preliminary ramming,whereas the A rear row of tamps serves for the ilnal ramming of theground. The tamping tools or rams are driven independently of the driveof the vehicle, the travelling speed and the dropping speed of thetamping tools being accurately regulated according to the existingcondition. 'lhe vehicle runs on endless tracks and wheels, rests andruns on the surface of the ground rammed by the first row of rams and istherefore ensured against irregular position and sinking.

The rams III, movable in vertical direction on corresponding guides,have shoes i2 adapted to the kind of work which has to be done and theycarry abutments i3 and i4 adjustable for varying the heights of drop andthe depths of drop. Chains I5 having catches engage centrally oreccentrically under the abutments I3 and lift, after having initiatedthe movement. the rams I0 to let them drop from the highest position,the drop weight acting upon the ground producing compression of theground. By corresponding mutual adjusting of the catches of the severalchains I5 it is obtained, that the rams in one row work in successionwhich may be changed as desired as shown for instance in Fig. 4. Toincrease the ramming effect of the rams, springs i6 are designed toimpart increased initial speed to the rams. 'I'he ram shoes l2 arepreferably in the shape of a rhomb or rhomboid as shown in Fig. 3 andmounted in such a manner that they overlap one another and thus ensurethat no portion of the ground remains unworked. 'I'he travelling speedof the machine is preferably regulated so that a portion of the groundcorresponding to the ramming surface of a ram shoe I2 is rammed abouteight times so that even the smallest portion of the ground is rammedseveral times and thoroughly compressed.

The shoes I2 are preferably of runner shape, the point of the runnerbeing preferably situated in the direction of travel indicated in Fig. 2by the arrow I1, whereby an uninterrupted, elastic treatment isobtained. 'Ihe beating surface of the shoe i2 is, as shown in Pig. 4,slightly concave to hold together the corresponding portion of theground, whereby the compressing is improved. Every ram guide Il is putunder the action of a spring I9 in the direction of travel in order thatthe ram, at the instant it comes into touch with the ground, does notimpede the travel of the vehicle, but yields elastically and resilientlyjumps forward as soon as it is lifted. The tension of the springs II canbe regulated or other suitable means may be substituted for thesesprings. 'Ihe rams III may evidently be operated by anytother suitablekind of device than the one described. The drive is, however, alwayssuch that the dropping speed is adapted to be adjusted to the travellingspeed of the vehicle, so that the individual rams can strike on to theground all at the same time in a closed row, so that the individual ramscan alternately 8,008,896 "The machineemployedi'or thisnanonmmegrounamamacsropmaz vand drop depth are separately adjustable forall lnuns together or singly for every ram.' `Ciwing to the lastmentioned arrangement-the crosssectional prole of the rammed groundmaybe altered.

Fig. 5 shows another type of ramming tool in the shape of aspring-hammer 2l, several ramming shoes i2 being also mounted in rows.

A reservoir 2i for stone material is also 1mounted on `the vehicle framehaving a discharge' mouth adapted to be regulated. If after thepreliminary ramming it is found that material is lacking on certainportions oi the track material is re-laid on these portions by openingthe reservoir or a chamber of the same, this material being thencompressed by the rams of the second row during the nal ramming.

To add binding matters, such as tar, bitumen or the like during the roadbuilding to the preliminariiy compressed road cover a tar pipe 22 fittedwith nozzles is arranged between the front and rear row of rams, towhich pipe the binding matter is supplied underpressure from a containermounted on the vehicle frame, so that the binding matter can beadjustably llll'yed on the road cover.

By the new machine for the production of tracks of any kind anotherimportant advantage is obtained, in that by the wedging of thesubstructure and super-structure or by the intimate compressing of thewhole bedding a cover of stone-concrete is produced without expansionjoints. 'Ihese joints form a great drawback of the concrete roads builtaccording to the commonly` used methods, in which roads such exp'ansionjoints are not to be omitted owing to the continual change oftemperature.

I claim:-

1. A machine for compressing the ground and building tracks of all kindscomprising in combination, a. self-propelled vehicle frame mounted onwheels, a transverse row of rams carried by the frame and extendingbeyond the wheel track, each ram including a ram-rod, a runner-like shoeon the lower end of said ram-rod and means for timing the operation ofthe individual ramrods in said row including an abutment verticallyadjustable on each ram-rod, a chain drive in proximity to said abutment,an adjustable catch on said chain cooperating with said abutment toperiodically lift said ram-rod to a height determined by the adjustmentof said abutment, a guide on the frame for vertically guiding saidram-rod and a spring on said ram-rod bearing against said guide, saidspring adapted to be compressed during the upward movement of saidram-rod and effect the downward' movement thereof.

2. A machine for compressing the ground and building tracks of all kindscomprising in combination, a self-propelled vehicle frame mounted onwheels, at least two transverse rows of rams overlapping in thedirection of travel, said rows being arranged one behind the other onsaid frame respectively adjacent the front and rear ends of the frameand extending beyond the wheel track, each ram including a ram-rod, arunner-like shoe on the lower end of said ramrod, an abutment verticallyadjustable on said ram rod, a chain drive in proximity to said abutment,an adjustable catch on said chain coopersaid abutment, a guide on theframe for verti- 7g cally guiding said rod, a. spring on said ram-rodbearing against said guide, said spring adapted to be compressed duringthe upward movement of said ram-rod and effect the downward movementthereof, and a. spring on said frame bearing against the rear side ofvsaid guide to exertvpressure thereon in a horizontal direction toresiliently maintain said ram-rod; in vertical position when out ofcontact with the ground and temporarily allow the same to yield towardsthe rear of the machine when said shoe is in contact with the ground.

3.\A machine for compressing the ground and building tracks .of allkinds comprising in combination a self-propelled vehicle frame mountedon wheels, a transverse row of rams carried by the frame and extendingbeyond the wheel track, each ram including a downwardly tensionedramrod, a runner-like shoe on the lower end of saidram-rod, means forperiodically lifting said ramrod against the tension thereon, a guide onthe frame for vertically guiding said ram-rod and a spring on said framebearing against the rear side of said guide to exert pressure thereon ina horizontal direction to resiliently maintain said ram-rod in verticalposition when out of contact with the ground and temporarily allow thesame to yield towards the rear of the machine when said shoe is incontact with the ground.

WILHELM LOTHAR VELTEN.

